Pratt & Whitney Rzeszów S.A.
MAINTENANCE MANUAL
PZL-10W ENGINE
70-02-00
1992,08,28
Page 202
Export Control Classification: PL/UE 9E999
(2) Torque wrench and extensions.
In some cases, it is necessary to use a special extension or adapter together with a standard
torque wrench (see Dwg. 201). If the wrench has been calibrated without the extension or
adapter, than in order to obtain the resultant required torque, the following formula shall be
used:
LT
LT
R = ----- = ---------
A
L + E
where: T - desired torque on the part
E - effective length of special extension or adapter
L - effective length of torque wrench
A - distance through which force is applied to part
R - reading on scale or torque wrench
Torque values are there in Nm (kGm; Lb.in), distance values in mm (in).
Example: A torque of 3,9 Nm (0,4 kGm; 34.72 Lb.in) is desired on a part when using a torque
wrench measuring 200 mm (7.87 in) from center of handle or handle swivel pin to
center of its square adapter, and special adapter having a length of 50 mm (1.97 in).
LT
200 * 3,9
R = ----- = ------------- = 3,12 Nm
A
200 + 50
200 * 0,4
(R = ---------------- = 0,32 kGm
200 + 50
7,87 * 34,72
R = ------------------ = 27,77 Lb.in)
7,87 + 1,97
With the axis of the extension or adapter and the torque wrench in a straight line, tightening
to a wrench reading of 3,12 Nm (0,32 kGm; 27.77 Lb.in) will provide the desired torque of 3,9
Nm (0,4 kGm; 34.72 Lb.in).